A visible factor of the special L-value

作者:Agashe Amod*
来源:Journal fur die Reine und Angewandte Mathematik, 2010, 644: 159-187.
DOI:10.1515/CRELLE.2010.055

摘要

Let A be a quotient of J(0)(N) associated to a newform f such that the special L-value of A (at s = 1) is non-zero. We give a formula for the ratio of the special L-value to the real period of A that expresses this ratio as a rational number. We extract an integer factor from the numerator of this formula; this factor is non-trivial in general and is related to certain congruences of f with eigenforms of positive analytic rank. We use the techniques of visibility to show that, under certain hypotheses ( which includes the first part of the Birch and Swinnerton-Dyer conjecture on rank), if an odd prime q divides this factor, then q divides either the order of the Shafarevich-Tate group or the order of a component group of A. Suppose p is an odd prime such that p(2) does not divide N, p does not divide the order of the rational torsion subgroup of A, and f is congruent modulo a prime ideal over p to an eigenform whose associated abelian variety has positive Mordell-Weil rank. Then we show that p divides the factor mentioned above; in particular, p divides the numerator of the ratio of the special L-value to the real period of A. Both of these results are as implied by the second part of the Birch and Swinnerton-Dyer conjecture, and thus provide theoretical evidence towards the conjecture.

  • 出版日期2010-7